Torso and Hip Muscle Activity and Resulting Spine Load and Stability while Using the ProFitter 3-D Cross Trainer

2009 ◽  
Vol 25 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Priyanka Banerjee ◽  
Stephen H.M Brown ◽  
Samuel J. Howarth ◽  
Stuart M. McGill

The ProFitter 3-D Cross Trainer is a labile surface device used in the clinic and claimed to train spine stability. The purpose of this study was to quantify the spine mechanics (compression and shear forces and stability), together with muscle activation mechanics (surface electromyography) of the torso and hip, during three ProFitter exercises. Trunk muscle activity was relatively low while exercising on the device (<25%MVC). Gluteus medius activity was phasic with the horizontal sliding position, especially for an experienced participant. Sufficient spinal stability was achieved in all three exercise conditions. Peak spinal compression values were below 3400 N (maximum 3188 N) and peak shear values were correspondingly low (under 500 N). The exercises challenge whole-body dynamic balance while producing very conservative spine loads. The motion simultaneously integrates hip and torso muscles in a way that appears to ensure stabilizing motor patterns in the spine. This information will assist with clinical decision making about the utility of the device and exercise technique in rehabilitation and training programs.

2021 ◽  
pp. 036354652110250
Author(s):  
Kelly R. Berckmans ◽  
Birgit Castelein ◽  
Dorien Borms ◽  
Thierry Parlevliet ◽  
Ann Cools

Background: Scapular muscle activity during shoulder exercises has been explored with surface electromyography (EMG). However, knowledge about the activity of deeper-layer scapular muscles is still limited. Purpose: To investigate EMG activation of the deeper-layer scapular stabilizers (levator scapulae [LS], rhomboid major [RM], pectoralis minor [Pm] muscles) together with superficial muscle activity (upper [UT], middle [MT], and lower trapezius [LT] and serratus anterior [SA]) during 4 exercises often used for training scapular function. Based on the amplitude EMG of the deeper-layer muscles, scapular muscle activation ratios for the 4 exercises were calculated, hereby providing knowledge of the optimal muscle balance. Study Design: Descriptive laboratory study. Methods: A total of 26 healthy participants performed 4 shoulder exercises (side-lying external rotation [ER], side-lying forward flexion, prone horizontal abduction with ER, and prone extension) while simultaneously measuring scapular muscle activity. Intramuscular electrodes were used for the deeper layer, in contrast to surface electrodes for the superficial muscles. All data were normalized to percentage of maximal voluntary isometric contraction (%MVIC), and the activation ratios (the muscle activity of the deeper layer relative to the other muscles) were calculated. A 1-way analysis of variance with Bonferroni correction was applied for statistical analysis. Results: Moderate activity was found in all exercises for the LS and RM (25%-45% MVIC). The Pm resulted in low activity during both side-lying exercises (13%-18% MVIC). Ratios involving LS or RM showed values >1 for all exercises (1.28-12.41) except for LS/MT, LS/LT, and LS/RM (0.85-0.98) during side-lying ER, and LS/MT, RM/MT and RM/LS (0.85-0.99) during side-lying forward flexion. Likewise, values <1 were found when MT (0.85) and LS (0.99) were involved with RM in the numerator during side-lying forward flexion. Ratios with Pm in the numerator showed values <1, apart from the ratios with UT and SA in the denominator. Conclusion: The study provides extended knowledge about the deeper-layer scapular muscle activity and related ratios during the 4 shoulder exercises mentioned here. Putting theory into practice, based on our results, we advise both side-lying exercises to be performed to strengthen LT and MT, even in case of hyperactivity of the Pm. However, the 4 exercises should be given carefully to patients with hyperactivity in the LS and/or RM. Clinical Relevance: The findings of this study may assist clinical decision making in exercise selection for restoring scapular function.


2015 ◽  
Vol 75 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Manfred J. Müller ◽  
Wiebke Braun ◽  
Maryam Pourhassan ◽  
Corinna Geisler ◽  
Anja Bosy-Westphal

The aim of this review is to extend present concepts of body composition and to integrate it into physiology. In vivo body composition analysis (BCA) has a sound theoretical and methodological basis. Present methods used for BCA are reliable and valid. Individual data on body components, organs and tissues are included into different models, e.g. a 2-, 3-, 4- or multi-component model. Today the so-called 4-compartment model as well as whole body MRI (or computed tomography) scans are considered as gold standards of BCA. In practice the use of the appropriate method depends on the question of interest and the accuracy needed to address it. Body composition data are descriptive and used for normative analyses (e.g. generating normal values, centiles and cut offs). Advanced models of BCA go beyond description and normative approaches. The concept of functional body composition (FBC) takes into account the relationships between individual body components, organs and tissues and related metabolic and physical functions. FBC can be further extended to the model of healthy body composition (HBC) based on horizontal (i.e. structural) and vertical (e.g. metabolism and its neuroendocrine control) relationships between individual components as well as between component and body functions using mathematical modelling with a hierarchical multi-level multi-scale approach at the software level. HBC integrates into whole body systems of cardiovascular, respiratory, hepatic and renal functions. To conclude BCA is a prerequisite for detailed phenotyping of individuals providing a sound basis for in depth biomedical research and clinical decision making.


Author(s):  
Seung-Min Baik ◽  
Heon-Seock Cynn ◽  
Chung-Hwi Yi ◽  
Ji-Hyun Lee ◽  
Jung-Hoon Choi ◽  
...  

BACKGROUND: The effectiveness of side-sling plank (SSP) exercises on trunk and hip muscle activation in subjects with gluteus medius (Gmed) weakness is unclear. OBJECTIVE: To quantify muscle activation of the rectus abdominis (RA), external oblique (EO), erector spinae (ES), lumbar multifidus (LM), Gmed, gluteus maximus (Gmax), and tensor fasciae latae (TFL) during SSP with three different hip rotations compared to side-lying hip abduction (SHA) exercise in subjects with Gmed weakness. METHODS: Twenty-two subjects with Gmed weakness were recruited. SHA and three types of SSP exercises were performed: SSP with neutral hip (SSP-N), hip lateral rotation (SSP-L), and hip medial rotation (SSP-M). Surface electromyography was used to measure the activation of the trunk and hip muscles. RESULTS: The trunk and hip muscles activations were generally significantly higher level during three SSP than SHA. SSP-M showed significantly lower EO activation while significantly higher ES and LM activation than SSP-L. Gmed activation was significantly higher during SSP-M than during SSP-L. TFL activation was significantly lower during SSP-M than during SSP-N and SSP-L. CONCLUSIONS: SSP could be prescribed for patients who have reduced Gmed strength after injuries. Especially, SSP-M could be applied for patients who have Gmed weakness with dominant TFL.


2018 ◽  
Vol 53 (11) ◽  
pp. 1071-1081 ◽  
Author(s):  
Cara L. Lewis ◽  
Hanna D. Foley ◽  
Theresa S. Lee ◽  
Justin W. Berry

ContextWeakness or decreased activation of the hip abductors and external rotators has been associated with lower extremity injury, especially in females. Resisted side stepping is commonly used to address hip weakness. Whereas multiple variations of this exercise are used clinically, few data exist regarding which variations to select.ObjectiveTo investigate differences in muscle-activation and movement patterns and determine kinematic and limb-specific differences between men and women during resisted side stepping with 3 resistive-band positions.DesignControlled laboratory study.SettingLaboratory.Patients or Other ParticipantsA total of 22 healthy adults (11 men, 11 women; age = 22.8 ± 3.0 years, height = 171.6 ± 10.7 cm, mass = 68.5 ± 11.8 kg).Intervention(s)Participants side stepped with the resistive band at 3 locations (knees, ankles, feet).Main Outcome Measure(s)We collected surface electromyography of the gluteus maximus, gluteus medius, and tensor fascia lata (TFL) for the moving and stance limbs during the concentric and eccentric phases. We also measured trunk inclination, hip and knee flexion, and hip-abduction excursion.ResultsHip-abductor activity was higher in women than in men (P ≤ .04). The pattern of TFL activity in the stance limb differed by sex. Women performed the exercise in greater forward trunk inclination (P = .009) and had greater hip excursion (P = .003). Gluteus maximus and medius activity increased when the band was moved from the knees to the ankles and from the ankles to the feet, whereas TFL activity increased only when the band was moved from the knees to the ankles. Findings were similar for both the stance and moving limbs, but the magnitudes of the changes differed.ConclusionsCompared with placing the band around the ankles, placing the band around the feet for resisted side stepping elicited more activity in the gluteal muscles without increasing TFL activity. This band placement is most appropriate when the therapeutic goal is to activate the muscles that resist hip adduction and internal rotation.


2010 ◽  
Vol 90 (2) ◽  
pp. 289-305 ◽  
Author(s):  
Judith M. Burnfield ◽  
Yu Shu ◽  
Thad Buster ◽  
Adam Taylor

Background People with physical disabilities often face barriers to regaining walking ability and fitness after discharge from rehabilitation. Physical therapists are uniquely positioned to teach clients the knowledge and skills needed to exercise on functionally relevant equipment available in the community, such as elliptical trainers. However, therapeutic use is hindered by a lack of empirical information. Objective The purpose of this study was to examine joint kinematics and muscle activation recorded during walking and elliptical training to provide evidence-based data to guide clinical decision making. Design This was a prospective, controlled laboratory study using a repeated-measures design. Methods Twenty adults free from impairments that might hinder gait participated. After familiarization procedures, subjects walked and trained on 4 elliptical devices while kinematic, electromyographic (EMG), and stride characteristic data were recorded. Results Movement similarities between elliptical training and walking were supported by the documentation of relatively high coefficients of multiple correlation for the hip (.85–.89), thigh (.92–.94), knee (.87–.89) and, to a lesser extent, the ankle (.57–.71). Significantly greater flexion was documented at the trunk, pelvis, hip, and knee during elliptical training than during walking. One of the elliptical trainers most closely simulated sagittal-plane walking kinematics, as determined from an assessment of key variables. During elliptical training, gluteus maximus and vastus lateralis muscle activation were increased; medial hamstring, gastrocnemius, soleus, and tibialis anterior muscle activation were decreased; and gluteus medius and lateral hamstring muscle activation were relatively unchanged compared with muscle activation of those muscles in walking. On the basis of EMG findings, no elliptical trainer clearly emerged as the best for simulating gait. Limitations To date, only 4 elliptical trainers have been studied, and the contributions of the upper extremities to movement have not been quantified. Conclusions Although one of the elliptical trainers best simulated sagittal-plane walking kinematics, EMG analysis failed to identify one clearly superior device. This research provides evidence-based data to help guide clinical decision making related to the use of elliptical trainers across the health care continuum and into the community.


2011 ◽  
Vol 46 (5) ◽  
pp. 476-483 ◽  
Author(s):  
Elizabeth C. Dalton ◽  
Kate R. Pfile ◽  
Gerald R. Weniger ◽  
Christopher D. Ingersoll ◽  
Daniel Herman ◽  
...  

Context: Anterior cruciate ligament (ACL) reconstructions are common, especially in young, active people. The lower extremity neuromuscular adaptations seen after aerobic exercise provide information about how previously injured patients perform and highlight deficits and, hence, areas for focused treatment. Little information is available about neuromuscular performance after aerobic exercise in people with ACL reconstructions. Objective: To compare dynamic balance, gluteus medius muscle activation, vertical jump height, and hip muscle strength after aerobic exercise in people with ACL-reconstructed knees. Design: Case-control study. Setting: Research laboratory. Patients or Other Participants: Of 34 recreationally active volunteers, 17 had a unilateral primary ACL reconstruction at least 2 years earlier and 17 were matched controls. Intervention(s): All participants performed 20 minutes of aerobic exercise on a treadmill. Main Outcome Measure(s): We recorded dynamic, single-legged balance electromyographic gluteus medius muscle activation, single-legged vertical jump height, and maximum isometric strength for hip abduction, extension, and external rotation preexercise and postexercise. Results: Participants with ACL reconstructions exhibited shorter reach distances during dynamic balance tasks, indicating poorer dynamic balance, and less gluteus medius muscle electromyographic activation. Reductions in hip abduction and extension strength after exercise were noted in all participants; however, those with ACL reconstructions displayed greater hip extensor strength loss after aerobic exercise than did the control group. Conclusions: Neuromuscular changes after aerobic exercise exist in both patients with ACL reconstructions and controls. The former group may experience greater deficits in hip extensor strength after aerobic exercise. Reduced reach distances in people with ACL reconstructions may represent a protective mechanism against excessive tibiofemoral rotation during dynamic balance. Clinicians should identify weaknesses in the resting state and after aerobic exercise in recreationally active patients and those with ACL reconstructions.


2016 ◽  
Vol 101 (4) ◽  
pp. 377-381 ◽  
Author(s):  
Steven Pauwels ◽  
Karel Allegaert

Therapeutic drug monitoring (TDM) aims to integrate drug measurement results into clinical decision making. The basic rules apply when using TDM in neonates (aminoglycosides, vancomycin, phenobarbital, digoxin), but additional factors should also be taken into account. First, due to both pharmacokinetic variability and non-pharmacokinetic factors, the correlation between dosage and concentration is poor in neonates, but can be overcome with the use of more complex, validated dosing regimens. Second, the time to reach steady state is prolonged, especially when no loading dose is used. Consequently, the timing of TDM sampling is important in this population. Third, the target concentration may be uncertain (vancomycin) or depend on specific factors (phenobarbital during whole body cooling). Finally, because of differences in matrix composition (eg, protein, bilirubin), assay-related inaccuracies may be different in neonates. We anticipate that complex validated dosing regimens, with subsequent TDM sampling and Bayesian forecasting, are the next step in tailoring pharmacotherapy to individual neonates.


2021 ◽  
Vol 34 ◽  
Author(s):  
Bibiana Melher Pereira ◽  
Marcelo Peduzzi de Castro ◽  
Cristiano Gomes Sanchotene ◽  
Caroline Ruschel ◽  
Gilmar Moraes Santos

Abstract Introduction: The inability to maintain good pelvic stability has been attributed to inefficient muscle coordination and deconditioning of the stabilizing muscles. Despite this, little is known about the role of the pelvic muscles in anteversion and retroversion movements. Objective: To compare the neuromuscular activity of the tensor fascia lata, gluteus medius, upper and lower portions of the gluteus maximus, and multifidus in pelvic anteversion and retroversion. Methods: The neuromuscular activity of 17 healthy young adults (aged 25.3 ± 4.6 years) was assessed during five repetitions of the pelvic anteversion and retroversion movements. The Vicon-Nexus system (10 cameras) was used for the kinematic analysis of the pelvis in the sagittal plane (anteversion and retroversion), and the TeleMyo DTS Desk Receiver electromyograph and the Myomuscle v. 3.8 software to measure neuromuscular activity. The paired samples t-test was used to compare muscle activity between pelvic anteversion and retroversion movements using the Statistica v.8 software with a significance level of p < 0.05. Results: The comparison of the movements showed greater muscle activity in the inferior gluteus maximus in retroversion and greater activity in the multifidus in pelvic anteversion. The upper portion of the gluteus maximus showed relevant activation in both movements. Conclusion: There was more pronounced activity of the lower portion of the gluteus maximus in retroversion, while the upper gluteus maximus showed relevant activation level in both movements. The multifidi were more active in retroversion.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255035
Author(s):  
Yuki Nakai ◽  
Masayuki Kawada ◽  
Takasuke Miyazaki ◽  
Sota Araki ◽  
Yasufumi Takeshita ◽  
...  

The importance of an interaction between trunk stability muscles and hip muscle function has been suggested. However, reported exercises rarely act on the trunk and hip muscles simultaneously. Here, we devised an abdominal oblique and hip muscle exercise, the Self-oblique exercise (SOE). We examined whether SOE activated abdominal and hip muscles in the supine and half-kneeling positions, compared with abdominal crunch (AC) and plank exercises; and whether participants could modulate the exercise load. Participants were 20 healthy males with some sports experience such as football and baseball on average 10.5 ± 4.0 years. Participants applied self-pressure to their right thighs using the contralateral upper limb with 40% or 70% of the maximum force in Supine SOE and Half- kneeling SOE. The following abdominal and hip muscles were measured using surface electromyography: bilateral external obliques (EO), bilateral internal obliques (IO), right rectus abdominis, right gluteus medius (GMed), and right adductor longus (ADD). All evaluated muscle groups showed significant differences between exercises (p < 0.001). Supine SOE-70% showed 80.4% maximal voluntary contraction (MVC) for left EO (p < 0.017), 61.4% MVC for right IO (p < 0.027), 24.3% MVC for GMed (p < 0.002), and 42.4% MVC for ADD (p < 0.004); these were significantly greatest among all exercises. Muscle activity during Supine SOE-70% was greater than that during Supine SOE-40%. Similarly, Half-kneeling SOE-40% promoted abdominal and hip muscle exertion, and showed more significant activity in GMed (p < 0.006) and ADD (p < 0.001) than AC and plank. SOE could activate abdominal and hip muscles depends on the pressure applied by upper limb. Also, SOE allows participants to modulate the exercise load in a self-controlled step by step manner. Modulation of the exercise load is difficult in AC or plank compared to SOE, and AC or plank cannot obtain simultaneous oblique and hip muscle activity. SOE could be practiced anywhere, in various positions, without any tools.


2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Hassam A. Baig ◽  
Daniel B. Dorman ◽  
Ben A. Bulka ◽  
Bethany L. Shivers ◽  
Valeta C. Chancey ◽  
...  

Whole body vibration has been postulated to contribute to the onset of back pain. However, little is known about the relationship between vibration exposure, the biomechanical response, and the physiological responses of the seated human. The aim of this study was to measure the frequency and corresponding muscle responses of seated male volunteers during whole body vibration exposures along the vertical and anteroposterior directions to define the transmissibility and associated muscle activation responses for relevant whole body vibration exposures. Seated human male volunteers underwent separate whole body vibration exposures in the vertical (Z-direction) and anteroposterior (X-direction) directions using sinusoidal sweeps ranging from 2 to 18 Hz, with a constant amplitude of 0.4 g. For each vibration exposure, the accelerations and displacements of the seat and lumbar and thoracic spines were recorded. In addition, muscle activity in the lumbar and thoracic spines was recorded using electromyography (EMG) and surface electrodes in the lumbar and thoracic region. Transmissibility was determined, and peak transmissibility, displacement, and muscle activity were compared in each of the lumbar and thoracic regions. The peak transmissibility for vertical vibrations occurred at 4 Hz for both the lumbar (1.55 ± 0.34) and thoracic (1.49 ± 0.21) regions. For X-directed seat vibrations, the transmissibility ratio in both spinal regions was highest at 2 Hz but never exceeded a value of 1. The peak muscle response in both spinal regions occurred at frequencies corresponding to the peak transmissibility, regardless of the direction of imposed seat vibration: 4 Hz for the Z-direction and 2–3 Hz for the X-direction. In both vibration directions, spinal displacements occurred primarily in the direction of seat vibration, with little off-axis motion. The occurrence of peak muscle responses at frequencies of peak transmissibility suggests that such frequencies may induce greater muscle activity, leading to muscle fatigue, which could be a contributing mechanism of back pain.


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